Connecting adapter for electric cable and fuse

ABSTRACT

An adapter for connecting an electric cable to a blade-type fuse characterized by two metal bodies, one of the bodies having a cable-receiving aperture and having a projecting portion extending from one side thereof, and the other body having a clamping surface adapted to receive the projecting portion in surface-to-surface contact. The adapter also includes clamping means associated with the clamping surface for retaining the projecting portion and a blade of a blade-type fuse in surfaceto-surface contact with each other.

ilnited States atent [1 1 Grad [ Sept. 18, 1973 1 CONNECTING ADAPTER FORELECTRIC CABLE AND FUSE [75] Inventor: John E. Grad, Beaver, Pa.

[73 Assignee: Westinghouse Electric Corporation,

Pittsburgh, Pa.

22 Filed: Feb. 22, 1972 211 App]. No.: 228,134

[52] 11.8. C1 339/265 F, 339/272 R [51] Int. Cl H01! 7/26, I-IOlr 7/12[58] Field of Search 339/31 R, 233, 237,

[56] References Cited UNITED STATES PATENTS 561,159 6/1896 Downes339/266 F 2,841,774 7/1958 Romanek;

281,576 7/1883 Stieringer 337/188 FOREIGN PATENTS OR APPLICATIONS3/1942' Germany 339/249 S OTHER PUBLICATIONS Electrical World; Dec,1965.

Primary ExaminerMarvin A. Champion Assistant ExaminerLawrence J. StaabAttorney-A. T. Stratton et a1.

[57] ABSTRACT An adapter for connecting an electric cable to a bladetypefuse characterized by two metal bodies, one of the bodies having acable-receiving aperture and having a projecting portion extending fromone side thereof, and the other body having a clamping surface adaptedto receive the projecting portion in surface-to-surface contact. Theadapter also includes clamping means associated with the clampingsurface for retaining the projecting portion and a blade of a blade-typefuse in surface-to-surface contact with each other.

2 Claims, 6 Drawing Figures PATENTED SEN 8 I975 SHEEI 1 0F 2CROSS-REFERENCE TO RELATED APPLICATION This invention is related to theinvention disclosed in the application of James B. Wallace et al, Ser.No. 228,133, filed Feb. 22, 1972.

BACKGROUND OF THE INVENTION switch equipment such as panelboardnectionbetween the jaws and a blade of a blade-type I fuse. The helper springsare necessary to maintain pressure on the jaws to carry the current andto avoid overheating between the bladeand the fuse jaws whichoverheating otherwise occurs between loose connections. A disadvantageof the helper springs, however, has been substantial difficulty ofinserting a fuse blade between the jaws. Indeed, it has become apractice to drive the blades into the jaws with a mallet or otherappropriate tool. As a result, the insulating bases of resinous materialin which the jaws are mounted are frequently broken.

Associated with the foregoing have been problems of assembly andproduction costs of the switches having fuse jaws adapted to acceptblade-type fuses.

SUMMARY OF THE INVENTION In accordance with this invention it has beenfound that the foregoing problems may be overcome by providing anadapter for connecting one or more electric face for retaining theprojecting body portion and a' blade of a blade-type fuse insurface-to-surface contact with each other.

The advantage of the adapter is that it combines a fuse clamp and a wireor cable terminal into two metal bodies which are readily securedtogether with'good electrical joints and thereby avoid sources of hotspots.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a plan view, with partsbroken away, of a multipole circuit interrupting device constructed inaccordance with the principles of this invention;

FIG. 2 is an enlarged, fragmentary, side elevational view of the adapterof this invention;

FIG. 3 is a sectional view taken on the line III'III of FIG. 2; 7

FIG. 4 is an isometric view of the adapter; and

FIGS. 5 and 6 are isometric views of other embodiments of thisinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention is illustrated asapplied to a circuit interrupter having an operating and contactmechanism of the type fully disclosed in U.S. Pat. No. 3,538,287, issuedNov. 3, 1970, to S. A. Mrenna, and assigned to the assignee of theinstant invention. For a complete understanding of the structure andoperation of the circuit interrupter mechanism, reference may be made tosaid U.S. Pat. No. 3,538,287. For brevity a limited description is madeof the circuit interrupter with which the adapter of this invention maybe used.

As shown in FIGS. 1 and 2 of the drawings there is disclosed a circuitinterrupter 5 comprising an enclosure 7 and an externally operablecircuit interrupter 9 supported on the enclosure 7. The enclosurecomprises a receptacle part 11 and an openable cover 13 supported on thereceptacle part for movement about hinges 15. The circuit interrupter 9is a three-pole circuit interrupter comprising a switch structure 17 anda fuse structure 19. The switch structure 17 comprises contact means 21for each pole and a common externally operable operating mechanism 23for simultaneously opening the three-pole units.

The operating mechanism 23 comprises an elongated handle lever 25 thatis fixed at the inner end thereof to a rod 29 that extends through anopening in the side wall of the receptacle. The lever 25 moves within ametallic hood 31 that is supported on the external side of thereceptacle. The circuit interrupting device 5 also includes a movablecontact structure 33 which is movable between opened and closed circuitpositions with a stationary contact structure 35 by manual operation ofthe handle lever 25 in a manner set forth in U.S. Pat. No. 3,538,287.

With the circuit interrupter in the closed position, the circuit througheach pole unit extends from a terminal connector 37 that is secured tothe stationary contact structure 35, the movable contact structure 33, aconducting blade 39, a fuse 41, and an adapter generally indicated at 43which includes a terminal connector or body member 45. The fuse 41includes flat plate terminals or blades 47 and 49, the former of whichis connected to the conducting plate 39 and the latter of which isconnected to the adapter 43.

In accordance with this invention, the adapter 43 connects the blade 49to a cable 77 (FIG. 3). For that purpose as shown more particularly inFIGS. 2, 3, and 4 the adapter comprises two metallic bodies (preferablycomposed of aluminum or copper) including the terminal connector 45 anda bracket 51. The connector 45 includes a projection 53 extending fromone side thereof which projection is clamped in surface-tosurfaceelectrical contact with the blade 49. The adapter 43 includes clampingmeans for holding the projection 53 and the blade 49 together.,Theclamping means comprises a clamping structure generally indicated at 55and includes a pressure bar 57 and a pair of bolts 59 for holdingopposite ends of the bar in place on the bracket 511.

As shown more particularly in FIGS. 3 and 4, the bracket Sll ispreferably provided with a notch 61 in which the projection 53 and theblade 49 are seated for maintaining the projection and the blade infixed aligned positions with respect to each other. Thus the projection53 and the blade 49 are secured between a bottom wall 63 of the notch 61and the pressure bar 57 where they are held in tight frictional contactwith each other to provide a good electrical current path therethrough.

In addition, the bracket 51 may be provided with a bolt 65 (FIG. 3) forholding a projection 53 in place within the notch 61 particularly whenthe fuse 51 is removed or replaced; thereby facilitating handling of theseveral parts.

In addition, the bracket 51 is provided with a mounting flange 67 havingspaced apertures 69 by which the adapter 43 is retained in place withinthe closure 7. The adapter 43 is mounted on a block 71 which is composedof an electrically insulating material and which in turn is secured bysuitable means such as space screws 73 to the bottom surface of theenclosure 7. For that purpose bolts (not shown) extend through theaperture 69 and into the block 71.

As shown in FIG. 3 the terminal connector 45 includes an aperture 75 inwhich the end portion of a wire or cable 77 is secured by suitableclamping means such as a set screw 79.

Another embodiment of the invention is shown in FIG. in which partssimilar to those of the embodiment shown in FIGS. 1 to 4 are identifiedwith similar reference numbers. An adapter generally indicated at 81 isa metallic body having aperture means such as a pair of spaced apertures83, a clamping surface 85, and a mounting flange 87. The adapter 81 isalso provided with suitable clamping means which includes the pressurebar 57 and spaced bolts 59, the latter of which are secured in threadedapertures in the adapter. Accordingly, the blade 49 of a fuse 51 isretained by the pressure bar 57 against the clamping surface 85 of theadapter 81 in surface-to-surface electrical contact. Suitable clampingmeans such as a set screw 89 for each aperture 83 are also provided forretaining a cable (not shown) in the apertures in a manner similar tothat shown in FIG. 3.

In FIG. 6 another embodiment of the invention includes an adaptergenerally indicated at 91 which is provided with aperture means such asan aperture 93, a clamping surface 95, and a mounting flange 97. Theclamping means for holding the blade 49 of the fuse 41 in electricalcontact with the clamping surface 95 of the adapter 91 is a bolt 99, thelower end of which is seated in a threaded aperture (not shown) in theadapter 91. Finally, clamping means such as a set screw 101 is providedwith the aperture 93 for retaining a cable in place in a manner similarto that shown in FIG. 3.

Accordingly, the adapter of the present invention satisfiesdisadvantages and problems inherent in prior known devices forconnecting electrical cables to bladetype fuses, and satisfies a longstanding need for a connector by reducing the number of connectingsurfaces between the fuse and the cable, thereby eliminating the sourcesof so-called hot spots which otherwise occur where loose contactingsurfaces exist.

What is claimed is:

1. An adapter for connecting an electric cable to a blade-type fuse, theadapter comprising two metal bodies, one of which bodies includes atleast one cablereceiving aperture and a set screw threadedly seated inthe body and movable into the aperture, said one body also comprising aprojection extending outwardly from one side thereof, the other of whichbodies includes a notch the bottom surface of which is a clampingsurface, the projection being seated in the notch, and clamping meansassociated with the clamping surface for holding the projection and theblade in surface-tosurface contact with each other.

2. The adapter of claim 1 in which the projection and a blade of ablade-type fuse are seated in the notch, and the clamping meanscomprises a pressure bar disposed across the notch.

1. An adapter for connecting an electric cable to a blade-type fuse, the adapter comprising two metal bodies, one of which bodies includes at least one cable-receiving aperture and a set screw threadedly seated in the body and movable into the aperture, said one body also comprising a projection extending outwardly from one side thereof, the other of which bodies includes a notch the bottom surface of which is a clamping surface, the projection being seated in the notch, and clamping means associated with the clamping surface for holding the projection and the blade in surface-to-surface contact with each other.
 2. The adapter of claim 1 in which the projection and a blade of a blade-type fuse are seated in the notch, and the clamping means comprises a pressure bar disposed across the notch. 